Dialkyl acetals of heterocyclic ureidoacetaldehyde

ABSTRACT

THIS INVENTION DISCLOSES NEW CHEMICAL COMPOUNDS OF THE FORMULA   2-(F3C-),5-(R1O-CH(-OR2)-CH2-N(-CH3)-CO-NH-)-1,3,4-THIADI   AZOLE   WHEREIN R1 AND R2 ARE EACH ALKYL OF UP TO 3 CARBON ATOMS/ FURTHER DESCRIBED ARE HERBICIDAL COMPOSITIONS UTILIZING THE ABOVE DEFINED COMPOSITIONS.

3,827,875 Patented Aug. 6, 1974 DIALKYL ACETALS F HETEROCYCLICUREIDOACETALDEHYDE Krenzer, Oak Park, Ill., assignor to VelsicolChemical Corporation, Chicago, Ill. No Drawing. Original applicationDec. 31, 1971, Ser. No. 207,529, now Patent No. 3,759,940. Divided andthis v application Apr. so, 1913, Ser. No. 355,387

us. CI. 71-90 Int. Cl. A01n 9/14 2 Claims ABST ACT OF THE DISCLOSUREThis invention discloses new chemical compounds of the formula wherein Rand R are each alkyl of up to 3 carbon atoms. Further described areherbicidal compositions utilizing the above defined compositions.

a division of application Ser. No. 207,529 filed Dec. 31, 1971, now Pat.No. 3,759,940. This invention relates to new compositions of matter andmore particularly relates to new chemical compounds v of the formulawherein R and R are each alkyl of up to 3 carbon atoms. The compounds ofthis invention are useful as herbicides 'and control a wide variety ofweeds without significantly damaging beneficial plants such as corn orrice.

The compounds of this invention can be readily prepared from theisocyanate dimer of the formula wherein R and R are each alkyl of up to3 carbon atoms. This reaction can be effected by heating a mixture of amolar amount of the isocyanate of formula II with about two molaramounts of the acetal of formula III in an inert organic reaction mediumsuch as benzene at the reflux temperature of the mixture. Heating atreflux can be continued for a period of from about 2 to about 30 minutesto ensure completion of the reaction. After this time the desiredproduct can be recovered upon evaporation of the reaction medium and canbe used as such or can be further purified by standard techniques in theart such as recrystallization and the like.

The compound of formula II can be prepared by the procedure detailed inExample 1. The preparation of Cir the compounds of the present inventionis more speci-fi cally illustrated in the following examples.

EXAMPLE 1 Preparation of 2-trifluoromethyl-l,3,4-thiadiazol-5-yl-is0cyanate dimer I A saturated solution of phosgene in ethylacetate (100 ml.) was charged into a glass reaction vessel equipped witha mechanical stirrer. A slurry of 2-trifluoromethyl-S-amino-l,3,4-thiadiazole grams) in ethyl acetate (300 ml.) was added tothe reaction vessel and the resulting mixture was stirred for a periodof about 16 hours resulting in the formation of precipitate. Thereaction mixture was then purged with nitrogen gas to remove unreactedphosgene. The purged mixture was filtered to recover 48 grams of a whitesolid. This solid Was recrystallized from dimethyl formamide to yieldthe desired product Z-trifluoromethyl-1,3,4-thiadiazol-5-yl isocyanatedimer.

EXAMPLE 2 Preparation of the dimethyl acetal of2-[3-(2-trifiu0romethyl-1,3 ,4-thiadiazol-5-yl ureido] acetaldehyde Amixture of Z-trifluoromethyl-1,3,4-thiadiazol-5-yl isocyanate dimer (9.5grams), the dimethyl acetal of 2- methylaminoacetaldehyde (5.8 grams)and benzene (60 ml.) are charged into a glass reaction vessel equippedwith a mechanical stirrer and reflux condenser. The reaction mixture isheated at reflux for a period of about 15 minutes. After this time themixture is stripped of benzene under reduced pressure to yield a solidproduct as the residue. This product was recrystallized from heptane toyield the desired product the dimethyl acetal of 2[3-(Z-trifluoromethyl-1,3,4-thiadiazol-5-yl)ureido] acetaldehyde havinga melting point of 101 to 102 C.

EXAMPLE 3 Preparation of the diethyl acetal of2-[3-(2-trifiuoromethyl-l,3,4-thiadiazol-5-yl)ureido]acetaldehyde Amixture of 2-trifluoromethyl-1,3,4-thiadiazol-5-yl isocyanate dimer (6grams), the diethyl acetal of Z-methylaminoacetaldehyde (4 grams) andbenzene ml.) is charged into a glass reaction flask equipped with amechanical stirrer and reflux condenser. The reaction mixture is heatedat reflux, with stirring for a period of about 10 minutes. After thistime the reaction mixture is stripped of benzene to yield a solidproduct. This product is recrystallized from pentane to yield thedesired product the diethyl acetal of 2-3-(2-trifluoromethyl-1,3,4-thiadiazol- S-yl ureido acetaldehyde.

EXAMPLE 4 Preparation of the diisopropyl acetal of 2-3-(2-trifluoromethyl-l,3,4-thiadiazol-5-yl)ureido acetaldehyde A mixtureof Z-tritluoromethyl-1,3,4-thiadiazol-5-yl isocyanate dimer (6 grams),the diisopropyl acetal of 2- methylaminoacetaldehyde (4.2 grams) andbenzene (50 ml.) is charged into a glass reaction flask equipped with amechanical stirrer and reflux condenser. The reaction mixture is heatedat reflux, with stirring for a period of about 10 minutes. After thistime the reaction mixture is stripped of benzene to yield a solidproduct. This product is recrystallized from pentane to yield thedesired product the diisopropyl acetal of2-[3-(2-trifiuoromethyl-1,3,4-thiadiazol-S-yl)ureido1acetaldehyde.

For practical use as herbicides the compounds of this invention aregenerally incorporated into herbicidal compositions which comprise aninert carrier and a herbicidally toxic amount of such a compound. Suchherbicidal able the active compound to be applied conveniently to thesite of the weed infestation in any desired quantity. These compositionscan be solids such as dusts, granules, or wettable powders; or they canbe liquids such as solutions, aerosols, or emulsifiable concentrates.

For example, dusts can be prepared by grindin and blending the activecompound with a solid inert carrier such as the tales, clays, silicas,pyrophyllite, and the like. Granular formulations can be prepared byimpregnating the compound, usually dissolved in a suitable solvent, ontoand into granulated carriers such as the attapulgites or thevermiculites, usually of a particle size range of from about 0.3 to 1.5mm. Wettable powders, which can be dispersed in water or oil to anydesired concentration of the active compound, can be prepared byincorporating wetting agents into concentrated dust compositions.

In some cases the active compounds are sufficiently soluble in commonorganic solvents such as kerosene or xylene so that they can be useddirectly as solutions in these solvents. Frequently, solutions ofherbicides can be dispersed under superatmospheric pressure as aerosols.However, preferred liquid herbicidal compositions are emulsifiableconcentrates, which comprise an active compound according to thisinvention and as the inert carrier, a solvent and an emulsifier. Suchemulsifiable concentrates can be extended with water and/or oil to anydesired concentration of active compound for application as sprays tothe site of the weed infestation. The emulsifiers most commonly used inthese concentrates are nonionic or mixtures of nonionic with anionicsurface-active agents. With the use of some emulsifier systems aninverted emulsion (water in oil) can be prepared for direct applicationto weed infestations.

A typical herbicidal composition according to this invention isillustrated by the following example, in which the quantities are inparts by weight.

EXAMPLE 5 Preparation of a dust Product of example l Powdered talc 90The above ingredients are mixed in a mechanical grinder-blender and areground until a homogeneous, freeflowing dust of the desired particlesize is obtained. This dust is suitable for direct application to thesite of the weed infestation.

The compounds of this invention can be applied as herbicides in anymanner recognized by the art. One method for the control of weedscomprises contacting the locus of said weeds with a herbicidalcomposition comprising an inert carrier and as an essential activeingredient, in a quantity which is herbicidally toxic to said weeds, acompound of the present invention. The concentration of the newcompounds of this invention in the herbicidal compositions will varygreatly with the type of formulation and the purpose for which it isdesigned, but generally the herbicidal compositions will comprise fromabout 0.05 to about 95 percent by weight of the active compounds of thisinvention. In a preferred embodiment of this invention, the herbicidalcompositions will comprise from about to about 75 percent by weight ofthe active compound. The compositions can also comprise such additionalsubstances as other pesticides, such as insecticides, nematocides,fungicides, and the like; stabilizers, Spreaders, deactivators,adhesives, stickers, fertiliz ers, activators, synergists, and the like.

The compounds of the present invention are also useful when combinedwith other herbicides and/or defoliants, desiccants, growth inhibitors,and the like in the herbicidal compositions heretofore described. Theseother materials can comprise from about 5% to about 95% of the activeingredients in the herbicidal compositions. Use of ompositions whichganalso be called formu lat i0ns, en.-

combinations 0.f. theseotherherbicides and/.or defoliants, desiccants,etc. with the compounds of the present invention provide herbicidalcompositions which are more effective in controlling weeds and oftenprovide results unattainable with separatecompositions of the individualherbicides. The other herbicides, defoliants, desiccants and plantgrowth inhibitors,- with which'the compounds of this invention can'be'used in the herbicidal compositions to control weeds, can'include'chlorophenoxy herbicides such as 2,4-D,. 2,4,5-T, MCPA, MCHB,flQA -DB), 2,4- DEB, 4-CPB, 4-CPA, 4-.CPP, 2,4,5-TB,. 2,4,5-TES,, DA,sil-vex and the like; carbamate herbicides such as IPC, CIPC, swep,barban, BCPC, CEPQ CPPC, and the like; thiocarbamate and dithiocarbamateherbicides such as CDEC, metham sodium, EPTC, diallate, P580, perbulate,vernolate and the like;" substituted urea herbicides such as norea,siduron, dichloral urea, chloroxyron, cycluron, fenuron, monuron,monuron TCA, diuron, linuron, monolinuron, neburon, buturon, trimeturonand the like; symmetrical triazine herbicides such as simazine,chlorazine, atraone, desmetryne, noraizne, ipazine, prometryn, atrazine,trietazine, simetone, prometone, propazine, ametryne, and the like;chloroacetamide herbicides such as alpha-chloro N,N dimethylacetamide,CDEA, CDAA, alpha-chloro N isopropylacetamide,2-chloro-N;isopropylacetanilide, 4-(chloroacetyumorpholine,1-(chloroacet yl)piperidine, and the like; ch l0rinated aliphaticacidherbicides such as TCA, dalapon, 2,3-dichloropropionic acid, 2,2,3-TPAand the like; chlorinated benzoic acid and phenylacetic acid herbicidessuch as 2,3,6'-TBA, 2,3,5,6 TBA, dicamba, tricam'ba, amiben, fe'nac,-PEA-,2- methoxy-3,6-dichlorophenylacetic a'cid,.-3-methoxy-2,6-dichlorophenylacetic acid,2-methoxy-3,5,6-trichlorophenylacetic acid, 2,4-dichloro-3-nitrobenzoicacid and the'like; and such compounds as aminotriazole, maleichydrazide, phenyl mercuric acetate, endothal, biuret, technicalchlordane, dimethyl 2,3,5;6-tetrachloroterephthalate, diquat, erbon,DNC, DNBP, dichlobenil, DPA, diphenamid, dipropalin, trifluoralin,solan, dicryl, merphos, DMPA, DSMA, MSMA, potassium azide, acrolein,benefin, bensulide, AMS, bromacil, 2-(3,4- dichlorophenyl)-4-methyl-124, oxadiazolidine 3,5 l dione, bromoxynil, cacodylic acid, CMA, CPMF,cypromid, DCB, DCPA, dichlone, diphenatril, DM'IT, DNAP, EBEP, EXD, HCA,ioxynil, IPX, isocil, potassium cyanate, MAA, MAMA, MCPES, MCPP, MH,molinate, NPA, OCH, paraquat, PCP, picloram, DPA, PCA, pyrichlor,sesone, terbacil, terbutol, TCBA, brominil, planavin, sodiumtetraborate, calcium cyanamid, DEF, ethyl xanthogen disulfide, sindone.sindone B, propanil and the like.

Such herbicides can also be used in the methods and compositions of thisinvention in the form of their salts, esters, amides, and otherderivatives whenever applicable to the particular parent compounds.

Weeds are undesirable plants growing where they are not wanted, havingno economic value, and interfering with the production of cultivatedcrops, with the growing of ornamental plants, or with the welfare oflivestock. Many types of weeds are known, including annuals such aspigweed, lambsquarters, foxtail, crabgrass, wild mustard, fieldpenn'ycress, ryegrass, goose-grass, chickweed,

wild'oats, velvet leaf, pur'slane, barnyard grass, smartweed, knotweed,cocklebur, wild buckwheat, kochia, medic, corn cockle, ragweed,sowthistle, colfee-weed, croton, cuphea, dodder, fumitory, groundsel,hemp nettle, knowel, spurge, spurry, emex jungle rice, pondweed, dogfennel, carpetweed, morning glory, bedstraw, ducksalad and naiad;biennials such as wild carrot, matricaria, wild barley, campion,chamomile, burdock, mullein, roundleaved mallow, bull thistle,hounds-tongue moth mullein, and purple star thistle; or perennials suchas white cockle, perennial rye-grass, quackgrass, Johnson grass, Canadathistle, hedge bindweed, Bermuda grass, sheep sorrel, curly dock,nutgrass, field chickweed. dandelion, campanula, field bindweed, Russianknapweed, mesquite,

toadfiax, yarrow, aster, gromwell, horsetail, ironweed, sesbania,bulrush, cattail and wintercress.

Similarly, such weeds can be classified as broadleaf or grassy weeds. Itis economically desirable to control the growth of such weeds withoutdamaging beneficial plants or livestock.

The new compounds of this invention are particularly valuable for weedcontrol because they are toxic to many species and groups of weed whilethey are relatively nontoxic to many beneficial plants. The exact amountof compound required will depend on a variety of factors, including thehardiness of the particular weed species, weather, type of soil, methodof application, the kind of beneficial plants in the same area, and thelike. Thus, while the application of up to only about one or two ouncesof active compound per acre may be sufiicient for good control of alight infestation of weeds growing under adverse conditions, theapplication of ten pounds or more of active compound per acre may berequired for good control of a dense infestation of hardy perennialweeds growing under favorable conditions.

The herbicidal toxicity of the new compounds of this invention can beillustrated by many of the established testing techniques known to theart, such as preand post-emergence testing.

The herbicidal activity of the compounds of this invention wasdemonstrated by experiments carried out for the pre-emergence control ofa variety of weeds. In these experiments small plastic greenhouse potsfilled with dry soil were seeded with the various weed seeds. Twentyfourhours or less after seeding the pots were sprayed with water until thesoil was wet and the test compounds formulated as aqueous emulsions ofacetone solutions containing emulsifiers were sprayed at the indicatedconcentrations on the surface of the soil.

After spraying, the soil containers were placed in the greenhouse andprovided with supplementary heat as required and daily or more frequentwatering. The plants were maintained under these conditions for a periodof from 15 to 21 days, at which time the condition of the plants and thedegree of injury to the plants was rated on a scale of from 0 to 10, asfollows: 0=no injury, 1, 2=slight injury, 3, 4=moderate injury, 5,6=moderately severe injury, 7, 8, 9=severe injury and 10=death. Theeffectiveness of these compounds is demonstrated by the data in Table I.

The herbicidal activity of the compounds of this invention was alsodemonstrated by experiments carried out for the post-emergence controlof a variety of weeds. In these experiments the compounds to be testedwere formulated as aqueous emulsions and sprayed at the indicated dosageon the foilage of the weeds that have attained a prescribed size. Afterspraying, the plants were placed in a greenhouse and watered daily ormore frequently. Water was not applied to the foilage of the treatedplants. The severity of the injury was determined 10 to days aftertreatment and was rated on the scale of from 0 to 10 heretoforedescribed. The effectiveness of these compounds is demonstrated by thedata in Table II.

TABLE I Pre-emergence herbicide activity of the product of Ex. 2

Injury rating Rate in Weed lbs. acre Barnyard grass 10 10 10 Crabgrass 99 6 Downy brome 10 1O 7 F0 ail 10 10 9 Johnson grass- 9 9 8 Wild oats 1010 8 Coffee weed 10 1O 10 Curly dock- 1O 1O 8 vet leaf... 9 9 9 Wildmustard l0 10 10 TABLE II Post-emergence herbicide activity of theproduct of Ex. 2

Injury rating Rate in Weed lbs/acre Barnyard grass. 10 9 8 Crabgrass 1010 9 Downy brome-- 10 10 9 Foxtail 10 9 8 Johnson grass- 10 10 10 ildoats 10 10 8 1O 10 10 10 1O 7 9 9 5 10 10 1O 1O 10 7 at 10 10 9 Wildmustard 10 10 10 I claim:

1. A herbicidal composition comprising an inert carrier and as anessential active ingredient, in a quantity toxic to weeds, a compound ofthe formula wherein R and R are each alkyl of up to 3 carbon atoms.

2. A method of controlling weeds which comprises contacting said weedswith a herbicidal composition comprising an inert carrier and as anessential active ingredient, in a quantity toxic to weeds, 8. compoundof Claim 1.

References Cited UNITED STATES PATENTS 3,728,354 4/1973 Rucker 71-90 X3,726,892 4/1973 Cebalo 71-90 X 3,686,198 8/1972 Metzger et a1. 7190 X3,260,588 7/ 1966 Schroeder 71-90 X LEWIS GOTTS, Primary Examiner C. L.MILLS, Assistant Examiner US. Cl. X.R. 7173 CERTIFICATE OF CORRECTIONPat n N 3, 827, 875 Dated August '6 1974 1 7 -J 0hn Krerwer It iscertified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

E1 column 2 line 22 for 2[3-(2trifluoro" read 2-[l-methyl-3-2-trifluoroline 35 for '2-[3-(2-trifluoromethyL-l,3,4thiadiazol5-- yl)ureido]" read 2[1-methyl-3 (2-trifluorovmethyl-1,3,4-thiadiazol-5-yl)ureido] line 39 for "2[3-(2trifluoro" read2-[l-methyl-3 "(2-trifluorolines 5l arid 52 for 2-3-(2-trifluoromethyl--l,3,4-thiadiazol-S-yhureido acetaldehyde" read2-[1- methyl-3-(Z-trifluoromethyl-l,3,4thiadiazol-5yl)ureido]acetaldehyd.e

lines 55 and 56 for "2- 3-( 2--trifluoromethy.r-l,3,4-

thi adiazol-5-yl)ureido acetaldehyde" read 2-[1-methyl-3-(2-trifluoromethyl-l,3,4-thia&iazol- 5-yl)ureido]acetaldehyde and line 67 for "2-[3- (2-trifluoromethyl-l,3,4--thia-=-read L 2[l-methyl3(2trifluoromethyl-=-l,3,4-thia- Signed and sealed this21st day of January 1975.

(SEAL) Attes't:

MCCOY P Z. GIBSON JR. C. MARSHALL DANN Attestlng Officer v Oommissionerof Patents

